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NanoTrak Autoalignment Controller
3.9.2 Input/Output tab
Fig. 3.6 NanoTrak Settings panel - Input/Output Tab
Input Signal
Signal Source
- the input source can be set to PIN or a range of BNC voltage inputs.
The
PIN
Input option should be used when NanoTraking to optimise a PIN current
feedback signal. The TIA (trans impedence amplifier) input source should be
selected when using the rear panel Optical I/P connector or when an external
detector head is connected to the optional SMB connector. This option uses the
internal amplifier circuit and associated functionality (e.g. autoranging).
The BNC Input options should be used when NanoTraking to optimise a voltage
feedback signal. Typically, these inputs are selected when using an external
power meter which generates a voltage output. In this case the internal amplifier
circuit is bypassed and ranging functionality (as displayed on the GUI) is
inoperative. The input can be set to 1V, 2V 5V or 10V.
PIN (TIA) Reading Units
Units Mode
- this parameter specifies the units relating to the input signal
measured by the NanoTrak, and is applicable only if a PIN (TIA) input source has
been specified.
If
Amps
is selected, readings are displayed or returned in mA, i.e. the raw PIN
current input signal to the internal amplifier.
If
Watts
is selected, readings are displayed or returned in mW, using a
Amp:Watt calibration factor specified in the A/W Calibration parameter.
Note
This is not intended to be a calibrated power reading, but rather a convenient
mechanism for converting current to power. The calibration factor will usually be a
wavelength dependent property.